Visual Basic.NET - Extraer Iniciales de un TextBox

Dim iniciales As String = ""

For Each txt As String In TextBox1.Text.Split(" ")

    iniciales = iniciales & txt.First

Next

Dim iniciales As String = ""

Dim NombreCompleto As String

NombreCompleto=Trim(TextBox1.Text)

For Each txt As String In NombreCompleto.Split(" ")

    iniciales = iniciales & txt.First

Next

" crisostomo     zevallos"

Dim iniciales As String = ""

        Dim NombreCompleto As String

        NombreCompleto = Trim(TextBox1.Text)

        While NombreCompleto <> NombreCompleto.Replace("  ", " ")

            NombreCompleto = NombreCompleto.Replace("  ", " ")

        End While

        For Each txt As String In NombreCompleto.Split(" ")

            iniciales = iniciales & txt.Substring(0, 1)

        Next

txt.First

Dim iniciales As String = ""

Dim NombreCompleto As String

NombreCompleto=Trim(TextBox1.Text)

For Each txt As String In NombreCompleto.Split(" ")

 If Not String.IsNullOrEmpty(txt) Then

    iniciales = iniciales & txt.First

 En If

Next

Dim iniciales As String = TextBox1.Text.Split(" ").Aggregate("", Function(current, txt) current & txt.First)